linux-stable.git/include, branch v5.7.6

kretprobe: Prevent triggering kretprobe from within kprobe_flush_task

2020-06-24T15:49:25+00:00

commit 9b38cc704e844e41d9cf74e647bff1d249512cb3 upstream.

Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave.
My test was also able to trigger lockdep output:

 ============================================
 WARNING: possible recursive locking detected
 5.6.0-rc6+ #6 Not tainted
 --------------------------------------------
 sched-messaging/2767 is trying to acquire lock:
 ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0

 but task is already holding lock:
 ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&(kretprobe_table_locks[i].lock));
   lock(&(kretprobe_table_locks[i].lock));

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 1 lock held by sched-messaging/2767:
  #0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50

 stack backtrace:
 CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6
 Call Trace:
  dump_stack+0x96/0xe0
  __lock_acquire.cold.57+0x173/0x2b7
  ? native_queued_spin_lock_slowpath+0x42b/0x9e0
  ? lockdep_hardirqs_on+0x590/0x590
  ? __lock_acquire+0xf63/0x4030
  lock_acquire+0x15a/0x3d0
  ? kretprobe_hash_lock+0x52/0xa0
  _raw_spin_lock_irqsave+0x36/0x70
  ? kretprobe_hash_lock+0x52/0xa0
  kretprobe_hash_lock+0x52/0xa0
  trampoline_handler+0xf8/0x940
  ? kprobe_fault_handler+0x380/0x380
  ? find_held_lock+0x3a/0x1c0
  kretprobe_trampoline+0x25/0x50
  ? lock_acquired+0x392/0xbc0
  ? _raw_spin_lock_irqsave+0x50/0x70
  ? __get_valid_kprobe+0x1f0/0x1f0
  ? _raw_spin_unlock_irqrestore+0x3b/0x40
  ? finish_task_switch+0x4b9/0x6d0
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70

The code within the kretprobe handler checks for probe reentrancy,
so we won't trigger any _raw_spin_lock_irqsave probe in there.

The problem is in outside kprobe_flush_task, where we call:

  kprobe_flush_task
    kretprobe_table_lock
      raw_spin_lock_irqsave
        _raw_spin_lock_irqsave

where _raw_spin_lock_irqsave triggers the kretprobe and installs
kretprobe_trampoline handler on _raw_spin_lock_irqsave return.

The kretprobe_trampoline handler is then executed with already
locked kretprobe_table_locks, and first thing it does is to
lock kretprobe_table_locks ;-) the whole lockup path like:

  kprobe_flush_task
    kretprobe_table_lock
      raw_spin_lock_irqsave
        _raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed

        ---> kretprobe_table_locks locked

        kretprobe_trampoline
          trampoline_handler
            kretprobe_hash_lock(current, &head, &flags);  <--- deadlock

Adding kprobe_busy_begin/end helpers that mark code with fake
probe installed to prevent triggering of another kprobe within
this code.

Using these helpers in kprobe_flush_task, so the probe recursion
protection check is hit and the probe is never set to prevent
above lockup.

Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2

Fixes: ef53d9c5e4da ("kprobes: improve kretprobe scalability with hashed locking")
Cc: Ingo Molnar 
Cc: "Gustavo A . R . Silva" 
Cc: Anders Roxell 
Cc: "Naveen N . Rao" 
Cc: Anil S Keshavamurthy 
Cc: David Miller 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: stable@vger.kernel.org
Reported-by: "Ziqian SUN (Zamir)" 
Acked-by: Masami Hiramatsu 
Signed-off-by: Jiri Olsa 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error handlers

2020-06-24T15:49:17+00:00

commit 7b97d868b7ab2448859668de9222b8af43f76e78 upstream.

In the ext4 filesystem with errors=panic, if one process is recording
errno in the superblock when invoking jbd2_journal_abort() due to some
error cases, it could be raced by another __ext4_abort() which is
setting the SB_RDONLY flag but missing panic because errno has not been
recorded.

jbd2_journal_commit_transaction()
 jbd2_journal_abort()
  journal->j_flags |= JBD2_ABORT;
  jbd2_journal_update_sb_errno()
                                    | ext4_journal_check_start()
                                    |  __ext4_abort()
                                    |   sb->s_flags |= SB_RDONLY;
                                    |   if (!JBD2_REC_ERR)
                                    |        return;
  journal->j_flags |= JBD2_REC_ERR;

Finally, it will no longer trigger panic because the filesystem has
already been set read-only. Fix this by introduce j_abort_mutex to make
sure journal abort is completed before panic, and remove JBD2_REC_ERR
flag.

Fixes: 4327ba52afd03 ("ext4, jbd2: ensure entering into panic after recording an error in superblock")
Signed-off-by: zhangyi (F) 
Reviewed-by: Jan Kara 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200609073540.3810702-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

libata: Use per port sync for detach

2020-06-24T15:49:16+00:00

[ Upstream commit b5292111de9bb70cba3489075970889765302136 ]

Commit 130f4caf145c ("libata: Ensure ata_port probe has completed before
detach") may cause system freeze during suspend.

Using async_synchronize_full() in PM callbacks is wrong, since async
callbacks that are already scheduled may wait for not-yet-scheduled
callbacks, causes a circular dependency.

Instead of using big hammer like async_synchronize_full(), use async
cookie to make sure port probe are synced, without affecting other
scheduled PM callbacks.

Fixes: 130f4caf145c ("libata: Ensure ata_port probe has completed before detach")
Suggested-by: John Garry 
Signed-off-by: Kai-Heng Feng 
Tested-by: John Garry 
BugLink: https://bugs.launchpad.net/bugs/1867983
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

afs: Remove the error argument from afs_protocol_error()

2020-06-24T15:49:14+00:00

[ Upstream commit 7126ead910aa9fcc9e16e9e7a8c9179658261f1d ]

Remove the error argument from afs_protocol_error() as it's always
-EBADMSG.

Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

nfs: set invalid blocks after NFSv4 writes

2020-06-24T15:49:11+00:00

[ Upstream commit 3a39e778690500066b31fe982d18e2e394d3bce2 ]

Use the following command to test nfsv4(size of file1M is 1MB):
mount -t nfs -o vers=4.0,actimeo=60 127.0.0.1/dir1 /mnt
cp file1M /mnt
du -h /mnt/file1M  -->0 within 60s, then 1M

When write is done(cp file1M /mnt), will call this:
nfs_writeback_done
  nfs4_write_done
    nfs4_write_done_cb
      nfs_writeback_update_inode
        nfs_post_op_update_inode_force_wcc_locked(change, ctime, mtime
nfs_post_op_update_inode_force_wcc_locked
   nfs_set_cache_invalid
   nfs_refresh_inode_locked
     nfs_update_inode

nfsd write response contains change, ctime, mtime, the flag will be
clear after nfs_update_inode. Howerver, write response does not contain
space_used, previous open response contains space_used whose value is 0,
so inode->i_blocks is still 0.

nfs_getattr  -->called by "du -h"
  do_update |= force_sync || nfs_attribute_cache_expired -->false in 60s
  cache_validity = READ_ONCE(NFS_I(inode)->cache_validity)
  do_update |= cache_validity & (NFS_INO_INVALID_ATTR    -->false
  if (do_update) {
        __nfs_revalidate_inode
  }

Within 60s, does not send getattr request to nfsd, thus "du -h /mnt/file1M"
is 0.

Add a NFS_INO_INVALID_BLOCKS flag, set it when nfsv4 write is done.

Fixes: 16e143751727 ("NFS: More fine grained attribute tracking")
Signed-off-by: Zheng Bin 
Signed-off-by: Anna Schumaker 
Signed-off-by: Sasha Levin

include/linux/bitops.h: avoid clang shift-count-overflow warnings

2020-06-24T15:49:04+00:00

[ Upstream commit bd93f003b7462ae39a43c531abca37fe7073b866 ]

Clang normally does not warn about certain issues in inline functions when
it only happens in an eliminated code path. However if something else
goes wrong, it does tend to complain about the definition of hweight_long()
on 32-bit targets:

  include/linux/bitops.h:75:41: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
          return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
                                                 ^~~~~~~~~~~~
  include/asm-generic/bitops/const_hweight.h:29:49: note: expanded from macro 'hweight64'
   define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w))
                                                  ^~~~~~~~~~~~~~~~~~~~
  include/asm-generic/bitops/const_hweight.h:21:76: note: expanded from macro '__const_hweight64'
   define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32))
                                                                             ^  ~~
  include/asm-generic/bitops/const_hweight.h:20:49: note: expanded from macro '__const_hweight32'
   define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16))
                                                  ^
  include/asm-generic/bitops/const_hweight.h:19:72: note: expanded from macro '__const_hweight16'
   define __const_hweight16(w) (__const_hweight8(w)  + __const_hweight8((w)  >> 8 ))
                                                                         ^
  include/asm-generic/bitops/const_hweight.h:12:9: note: expanded from macro '__const_hweight8'
            (!!((w) & (1ULL << 2))) +     \

Adding an explicit cast to __u64 avoids that warning and makes it easier
to read other output.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Andrew Morton 
Acked-by: Christian Brauner 
Cc: Andy Shevchenko 
Cc: Rasmus Villemoes 
Cc: Josh Poimboeuf 
Cc: Nick Desaulniers 
Link: http://lkml.kernel.org/r/20200505135513.65265-1-arnd@arndb.de
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

ASoC: dapm: Move dai_link widgets to runtime to fix use after free

2020-06-24T15:48:59+00:00

[ Upstream commit f4aa5e214eeaf7f1c7f157526a5aa29784cb6a1f ]

The newly added CODEC to CODEC DAI link widget pointers in
snd_soc_dai_link are better placed in snd_soc_pcm_runtime.
snd_soc_dai_link is really intended for static configuration of
the DAI, and the runtime for dynamic data.  The snd_soc_dai_link
structures are not destroyed if the card is unbound. The widgets
are cleared up on unbind, however if the card is rebound as the
snd_soc_dai_link structures are reused these pointers will be left at
their old values, causing access to freed memory.

Fixes: 595571cca4de ("ASoC: dapm: Fix regression introducing multiple copies of DAI widgets")
Signed-off-by: Charles Keepax 
Link: https://lore.kernel.org/r/20200526161930.30759-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown 
Signed-off-by: Sasha Levin

/dev/mem: Revoke mappings when a driver claims the region

2020-06-24T15:48:58+00:00

[ Upstream commit 3234ac664a870e6ea69ae3a57d824cd7edbeacc5 ]

Close the hole of holding a mapping over kernel driver takeover event of
a given address range.

Commit 90a545e98126 ("restrict /dev/mem to idle io memory ranges")
introduced CONFIG_IO_STRICT_DEVMEM with the goal of protecting the
kernel against scenarios where a /dev/mem user tramples memory that a
kernel driver owns. However, this protection only prevents *new* read(),
write() and mmap() requests. Established mappings prior to the driver
calling request_mem_region() are left alone.

Especially with persistent memory, and the core kernel metadata that is
stored there, there are plentiful scenarios for a /dev/mem user to
violate the expectations of the driver and cause amplified damage.

Teach request_mem_region() to find and shoot down active /dev/mem
mappings that it believes it has successfully claimed for the exclusive
use of the driver. Effectively a driver call to request_mem_region()
becomes a hole-punch on the /dev/mem device.

The typical usage of unmap_mapping_range() is part of
truncate_pagecache() to punch a hole in a file, but in this case the
implementation is only doing the "first half" of a hole punch. Namely it
is just evacuating current established mappings of the "hole", and it
relies on the fact that /dev/mem establishes mappings in terms of
absolute physical address offsets. Once existing mmap users are
invalidated they can attempt to re-establish the mapping, or attempt to
continue issuing read(2) / write(2) to the invalidated extent, but they
will then be subject to the CONFIG_IO_STRICT_DEVMEM checking that can
block those subsequent accesses.

Cc: Arnd Bergmann 
Cc: Ingo Molnar 
Cc: Kees Cook 
Cc: Matthew Wilcox 
Cc: Russell King 
Cc: Andrew Morton 
Cc: Greg Kroah-Hartman 
Fixes: 90a545e98126 ("restrict /dev/mem to idle io memory ranges")
Signed-off-by: Dan Williams 
Reviewed-by: Kees Cook 
Link: https://lore.kernel.org/r/159009507306.847224.8502634072429766747.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

mfd: stmfx: Disable IRQ in suspend to avoid spurious interrupt

2020-06-24T15:48:56+00:00

[ Upstream commit 97eda5dcc2cde5dcc778bef7a9344db3b6bf8ef5 ]

When STMFX supply is stopped, spurious interrupt can occur. To avoid that,
disable the interrupt in suspend before disabling the regulator and
re-enable it at the end of resume.

Fixes: 06252ade9156 ("mfd: Add ST Multi-Function eXpander (STMFX) core driver")
Signed-off-by: Amelie Delaunay 
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

usb: gadget: Fix issue with config_ep_by_speed function

2020-06-24T15:48:55+00:00

[ Upstream commit 5d363120aa548ba52d58907a295eee25f8207ed2 ]

This patch adds new config_ep_by_speed_and_alt function which
extends the config_ep_by_speed about alt parameter.
This additional parameter allows to find proper usb_ss_ep_comp_descriptor.

Problem has appeared during testing f_tcm (BOT/UAS) driver function.

f_tcm function for SS use array of headers for both  BOT/UAS alternate
setting:

static struct usb_descriptor_header *uasp_ss_function_desc[] = {
        (struct usb_descriptor_header *) &bot_intf_desc,
        (struct usb_descriptor_header *) &uasp_ss_bi_desc,
        (struct usb_descriptor_header *) &bot_bi_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_ss_bo_desc,
        (struct usb_descriptor_header *) &bot_bo_ep_comp_desc,

        (struct usb_descriptor_header *) &uasp_intf_desc,
        (struct usb_descriptor_header *) &uasp_ss_bi_desc,
        (struct usb_descriptor_header *) &uasp_bi_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_bi_pipe_desc,
        (struct usb_descriptor_header *) &uasp_ss_bo_desc,
        (struct usb_descriptor_header *) &uasp_bo_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_bo_pipe_desc,
        (struct usb_descriptor_header *) &uasp_ss_status_desc,
        (struct usb_descriptor_header *) &uasp_status_in_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_status_pipe_desc,
        (struct usb_descriptor_header *) &uasp_ss_cmd_desc,
        (struct usb_descriptor_header *) &uasp_cmd_comp_desc,
        (struct usb_descriptor_header *) &uasp_cmd_pipe_desc,
        NULL,
};

The first 5 descriptors are associated with BOT alternate setting,
and others are associated with UAS.

During handling UAS alternate setting f_tcm driver invokes
config_ep_by_speed and this function sets incorrect companion endpoint
descriptor in usb_ep object.

Instead setting ep->comp_desc to uasp_bi_ep_comp_desc function in this
case set ep->comp_desc to uasp_ss_bi_desc.

This is due to the fact that it searches endpoint based on endpoint
address:

        for_each_ep_desc(speed_desc, d_spd) {
                chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
                if (chosen_desc->bEndpoitAddress == _ep->address)
                        goto ep_found;
        }

And in result it uses the descriptor from BOT alternate setting
instead UAS.

Finally, it causes that controller driver during enabling endpoints
detect that just enabled endpoint for bot.

Signed-off-by: Jayshri Pawar 
Signed-off-by: Pawel Laszczak 
Signed-off-by: Felipe Balbi 
Signed-off-by: Sasha Levin